| 摘要 |
This invention relates to an improvement in the process for the production of water-adsorbing, but at least partially water-insoluble cellulose ethers in which cellulose is alkalized in a liquid reaction medium and etherified in a manner such that by etherification only an at least largely water-soluble carboxymethyl cellulose, carboxymethyl hydroxyethyl cellulose, hydroxyethyl cellulose or methyl hydroxyethyl cellulose is produced, and in which the cellulose is reacted in an alkaline reaction medium before, during, or after the etherification with a modification agent reactive with the still free hydroxyl groups of the cellulose anhydro glucose groups, said modification agent having one of the formulae <IMAGE> I <IMAGE>II in which R1 is hydroxyl, an acylamino or esterified carbamino group, and R2 is hydrogen or a carboxyl group, THE IMPROVEMENT COMPRISING EFFECTING ALKALIZATION, ETHERIFICATION, AND MODIFICATION IN A LIQUID REACTION MEDIUM OTHER THAN ISOPROPYL ALCOHOL. |
